Sand blasting machine



c. J. KAMMERER ETAL SAND BLASTING MQCHINE 3 Sheets-Sheet 1 Filed June 9, 19.47

//vv/v RS C.J. KAMMERER A.N. MAC K/NNON ATTORNEY Oct. 11, 1949. c. J. KAMMERER EI'AL' ,5

SAND BLASTING MACHINE 3 Sheets-Sheet 2 Filed June 9. 1947 lNlENTO/PS C.J. KAMMERER A.N. MAC K/NNON A T TORNEV Ot. 11, 1949. c. J. KAMMERER TAL SAND BLASTING MACHINE- 3 Sheets-:Sheet 3 Fiied June 9. 1947 m WW X k k l l I BY MM ATTORNEY Patented Oct. 11, 1949 UNITED iLSfTAT. ES

T OFF 1 CE This invention relates'tosandblasting machines, and more particularly to worksupports therein.

In the manufacture of quartzcrystal structures for use-in the communication arts, certain of the crystal wafers have sliver coatings on opposing surfaces thereof 'which insome instances-are divided in two or more parts to form a-multiple crystal unit. To divide the silver coatings in'two ormore'pa-rts, these i parts mustbe completely. separated fromeach other, although the-line of separationmay be relatively'narrow. Ithas been found advantageous-to form theseparating line --or lines in the silver coatings byabrasive particles forced'byair under-pressure tothe restricted areas forthe separating lines. To accomplish this result satisfactorily, that is, to produce dividing lines-in the silver coatings by uniform action-on the article or coated crystal throughout the lengths of the dividing lines, it--is importantthatthe crystal be :moved in a-straight line relative to theunit forcing the abrasive particles toward the crystal.

An object of the invention-isto-provide a carriage suitable fort-supporting and reciprocating work in a given planein asand blasting machine.

The salient feature of this invention -includes a carriagef-or-l an article, in' an abrasive machine such' as a sand blasting machine, wherein the carriage is supported for movement in a given plane relative to"the='abr'asive unit. An element supporting the carriage is mounted for movement in a'bearing while a flexible covering surrounds the bearing and theportion' of the element movable 'inthe bearing during reciprocation of the carriage. I

More specifically, the carriage is in thef-orm of a table or mask having a slot thereincomparable-in width and contour-tothe dividing line to be formed in the coating on the article. In the present embodiment-of "the invention, the carriage-is supported by parallel rods movable longitudinally in spaced-pairs of-bearings surrounded by hoods 'of"flexib'le material secured to their bearings and to given portions of the rods whereby the rods may be moved longitudinally to move the carriage between given limits. During movement of the rods with the carriage, the hoods completely enclose not only the bearings, but those portions of the rods which will move in the bearings preventing the abrasive material from entering the bearings and causing damage thereto.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with-the accompanying drawings, wherein Fig. 1-isa-front elevational view of an abrasive. machine embodying-the invention, portions of the machine being shown in section;

Fig. 2-is a -side= elevational view of the machine;

Fig 3 is an enlarged-fragmentarysectional view taken alongtheiline 33 of Flg. .1; and

Fig. 4 is a perspective view ofone .of the arti cles.

Referring now to the drawings, attention is first directed toiEig. 4-.which'. illustrates a quartz crystalwafer -Ill-having coatings ll of material such as silver on. opposing sides thereof. The thicknesses of the coatings,- as well as the thickness of the crystal, are-exaggerated for the purpose of illustration. -In the present embodiment ofthe inventionfthecoatings I lareto be divided intotwo 'equal.:parts along a straight line 12. Thesecoatings-couldbedivided into more than twoparts and the-line of division could be other than a straight-linen so. desired. Attention-is now directed-to Fig. 3 which illustrates acarriageiiintheform ofa tableor mask having a' locating -member 16 mounted on its upper surface to locate-the article or crystal l0 withrespect toanelongate opening l'L The table I5 is"mounted on parallel rods 18 which may berdefinedtas GIQIlgfitQBIEHlEIltS. The rods IB in the present embodiment of the invention are square 7. in .cross-section": portionsthereof being provided with; additional -flat surfaces IQ for the mounting of the-table l5thereon. A The rods 18 extend through bearings 20 which are supported in: side walls 21 0f a. compartment 22 (Figl .l')- of thesmain irameilof the machine. Outer bearing portions fidortherods 18 are secured to theouter surfaces of the walls 2| externally of thecompartmeht 22. The walls of the :compart-ment- ZZ. surround the carriage l 5' together with the bearings -20 on all sidesexcepting the front which is open. whereby the operator may gain access to the carriage for the positioning of the crystals thereon. The bearings 20, as well as the bearing members 25, have square openings therein conforming to the crosss-sectional contours of the rods l8 permitting longitudinal movement of the rods in the bearings.

Flexible coverings or hoods 28 completely surround portions of the rods I8, as well as their bearings 20 to protect them against the abrasive material. The coverings 28 are substantially conical when extended their full lengths as illusrods to seal the smaller ends of the coverings to" the rods.

An abrasive unit 33 in the form of a sand blast nozzle is mounted at a fixed position beneath the compartment 22 and the elongate aperture I! in the carriage l5. Abrasive material 34 is supplied to the unit 33 through a tube 35 in the conventhe compartment toward and through the elongate aperture I! in the carriage l5. In this manner, the coating H on the underside of the article I is removed along a line control by the aperture ll. By applying the abrasive material vertically to the article through the aperture 9! the material, after striking the article and accomplishing its purpose, may drop freely from the article. The particles of the abrasive material which enter the compartment 22 may fall upon the carriage l or the hood-like coverings 28, but none of these particles will rest upon the portions of the rods l8 which, during their movements,

will'enter or pass through the bearings 20. Furtional manner by the forcing of air from a supply line 36 (Fig. 2) through a valve 31 and air lines 38 (Figs. 1 and 2) and 39 to the unit 33.

The carriage is moved through an operating cycle from a starting position to a given position away from the starting position and back to the starting position by a driving mechanism which is the subject matter of the copending application of Harry H. Merwin, Serial No. 753,535, filed June 9, 1947, now Patent No. 2,463,895, dated March 8,

1949. This driving mechanism is shown in general in Figs. 1 and 2 and includes a drive motor 4|, a speed reducing unit 42 driven by the motor and a clutch 43 on the output shaft of the unit 42 to drive a shaft 44 one revolution during each cycle of operation. The clutch is actuated by a mechanism, disposed in a unit 45, through the actuation of a treadle 46 to move a bell crank lever 41, moving a rod 48 to release the clutch for one revolution. A cam (not shown) is mounted on the shaft 44 to pull a rod 50 downwardly to open the valve 31 at the start of the movement of the carriage and to hold the valveoperated until the carriage again returns to its starting position.

A flywheel 52 mounted on the shaft 44 carries a stub shaft 53 eccentrically as shown in Fig. 1 with respect to the axis of the shaft 44 to actuate a'link 54 and a lever 55. The lever 55 has its upper end fixed to a shaft 56 journalled in a bearing bracket 51, the shaft 56 causing actuation of a lever 58 which extends upwardly between the adjacent ends of the rods I8. 'The adjacent ends of the rods [8 are'connected to each other by a lateral member 68, the member 68 extending through an elongate opening 6| in the upper end of the lever 58.

During operation of the abrasive machine by the actuation of thetreadle 46 to bring about one cycle of operation of the driving mechanism, the carriage I5 is moved from the position shown in Figs. 1 and 3 to a similar position near the right wall of the compartment 22 and backto the starting position shown in these figures. During this movement of the carriage, the valve 3? is open allowing air under pressure to pass through the unit 33 "creating a vacuum therein to draw abrasive material 34 through the tube and force this material through an opening 85 at the bottom of thermore, the bearings 20 are sealed against the abrasive particles and in this manner, long useful life of the work supporting structure is assured.

Although specific improvements of th invention have been shown and described, it will be understood that they are but illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as defined by the appended claim.

What is claimed is:

In a sand blasting machine having a compartment with an opening in the bottom thereof through which abrasive material such as sand may be forced in a given path upwardly from a sand blasting unit positioned externally of the compartment, spaced parallel rods traversing the compartment and extending through pairs of aligned apertures in walls of the compartment, bearings to support the rods for reciprocable movement mounted in the said apertures, a Work supporting carriage with an elongate aperture therein mounted on the rods for reciprocation therewith whereby the elongate aperture may be moved over the opening and traverse the path of the abrasive material, means operable to reciprocate the bars in unison to move the carriage between given limits, fiexible hoods completel surrounding the bearings within the compartment and the portions of the rods movable in their bearings during reciprocation of the rods and carriage to seal the bearings and the rod portions against the abrasive material, and clamps to secure and form sealtight connections f the ends of the hoods to their bearings and rod portions.

CHARLES J. KAMMERER. ANDREW N. MACKIN N 0N REFERENCES CITED 7 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 955,468 Motz Apr. 19, 1910 2,020,891 Hoover et'al. Nov. 12, 1935 2,401,165 Knapp May 28, 1946 FOREIGN PATENTS Number Country Date 25,944 Great Britain Nov. 8, 1897 

